Compelling evidence that broken windows theory of crime is true

Thebroken windows theoryis acriminologicaltheory of the norm-setting and signaling effect of urban disorder andvandalismon additionalcrimeandanti-social behavior. The theory states that maintaining and monitoringurban environmentsto prevent small crimes such asvandalism, public drinking and toll-jumping helps to create an atmosphere of order and lawfulness, thereby preventing more serious crimes from happening.

The theory was introduced in a 1982 article by social scientistsJames Q. WilsonandGeorge L. Kelling. Since then it has been subject to great debate both within thesocial sciencesand the public sphere. The theory has been used as a motivation for several reforms in criminal policy, including the controversial mass use of “stop, question, and frisk” by theNew York City Police Department.

Remember – it is the theoretical basis of NYC’s terrible stop and frisk policy!

Now here is some of the evidence, from 9 different studies:

1. Bikes are parked in a row next to a fence with a conspicuous “no graffiti” sign, and flyers are attached to each bicycle such that they must be removed to use the bike. If no graffiti is on the fence, 33% of subjects will litter their flyers. If graffiti is on the fence, 69% will. This was so surprising that a news station paid the researchers to replicate the study while they watched from rented rooms looking down on the area. The finding replicated very closely, and now the Netherlands requires immediate removal of graffiti.

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7. A bike is on the ground in an alley, having apparently accidentally fallen off its stand. If passersby have just entered the alley from an empty, clean street, 20% of individuals and 27% of groups right the bicycle. If garbage bags had been left on the street, then 6% of individuals and 5% of groups did so. If prior to entering the alley, passersby passed by someone who dropped an aluminum can and then picked it back up, 34% of individuals and 35% of groups picked up the bike.